1. Field of the Invention
This invention relates to a station for a processing line which automatically cuts an end off of the casings on a succession of sausages, such as pepperoni, and strips the casings from the sausages, the casings having been loosened on the sausages at a previous station on the processing line.
2. Description of the Related Art
Pepperoni and other dry sausages are produced by stuffing meat, seasonings, curing salts, and a starter mixture of selected bacteria into a casing which was traditionally made of animal intestine. Today, the casings are more typically made of a synthetic material. The casing is closed at each end either by tying or by a metal clip. After the sausages have been stuffed, they are placed on racks in a fermentation room where the bacteria produce lactic acid. It is the presence of this lactic acid, in addition to the seasonings, which gives the sausage its familiar tangy flavor. After fermentation, the racks of sausages are moved to a drying room where they remain for several weeks until the proper water content is reached.
Pepperoni is most often used in sliced form on pizza, in sandwiches and salads, and in other foods. Commercial pepperoni producers slice and package the pepperoni in bulk for use in preparing these food items. Before the pepperoni can be sliced, however, the sausage must first be removed from the casing, which is inedible. Modem synthetic casings are reusable and therefore it is advantageous to remove the casings from the pepperoni in such a manner that the casings are not damaged.
Pepperoni casings have traditionally been removed by labor intensive hand removal methods. In one such method, the sausages are brought into a processing area on their drying racks, usually by means of a fork lift. Each sausage is then manually removed from the rack. A worker then takes a sausage and inserts a probe connected to an air hose into one end of the casing. The worker partially inflates the casing, causing the casing to begin to separate from the pepperoni. By xe2x80x9cmassagingxe2x80x9d the sausage between his hands, the worker moves the air around inside the casing, forcing the air between the casing and the pepperoni, and thereby completes the separation process. The worker then cuts off the tie or clip. The casing can then be pulled off of the pepperoni.
In today""s market, increased demand for sliced pepperoni for use on pizzas and escalating labor costs have made inefficient manual casing removal techniques undesirable. Unfortunately, however, the automated casing removal machines which have been known previously have not been able to perform the casing removal task as well as can be done by hand.
U.S. Pat. No. 6,080,055 issued to Lyndon R. Leining et al. and entitled xe2x80x9cMethod and Apparatus for Stripping Cases From Sausagesxe2x80x9d discloses such an automated machine. In this device, pepperoni sausages are placed on an indexing conveyor which moves the sausages two at a time through a series of stations. At the first station, air is injected into the sides of the casings proximate each end thereof At the second station, the casings are scored along a transverse line near each end, defining an end cap, and each end cap is pulled off At the third station, a longitudinal cut is made down the length of each casing. At the fourth station, gripping fingers grab the casing and pull it off the sausage. While this machine is capable of automatically removing the casings from pepperoni, the casings are destroyed in the process and cannot be reused.
U.S. Pat. No. 4,463,641 issued to Eiichi Sato discloses a device for cutting knotted ends off of xe2x80x9ctube bagsxe2x80x9d containing meat products. This is done in order to make the product easier to package. The device includes an annular stopper which engages the end of the bagged product and a pair of pliers which grasp the bag proximate the sealing clip. The pliers are then puffed away from the stopper to stretch the portion of the bag located therebetween. The bag is then cut between the pliers and the stopper by a cutter blade. The inventor likens the process used by the device to cutting the head off a turtle, stating that xe2x80x9cthe retracted turtle""s neck must be drawn out before being cut off.xe2x80x9d
The present invention is a casing end-cutting and stripping station for removing the casings from a succession of sausages. The end-cutting and stripping station is part of a sausage processing line which includes a casing disengaging station which loosens the casings on the sausages prior to their reaching the end-cutting and stripping station. The sausages are suspended from a main conveyor by respective string loops such that they hang generally vertically downward. The main conveyor carries the sausages through the disengaging station to the end-cutting and stripping station.
The end-cutting and stripping station comprises a carousel mounted for rotation about a generally vertical axis, the carousel including a plurality of casing end-cutting units circumferentially spaced around the perimeter thereof The carousel is operatively connected to the main conveyor such that each end-cutting unit receives a respective sausage as the main conveyor advances.
Each end-cutting unit includes a frame member removably attached to the carousel and sausage support for supporting a sausage connected to the frame member. A carriage is slidably mounted to the frame member below the sausage support. A pair of sensor fingers are pivotally mounted to the carriage such that they extend upwardly from the carriage toward the sausage support. The tips of the sensor fingers are angled inwardly toward one another. A lever arm is connected to each sensor finger proximate its pivot point. Each lever arm is generally transverse to its respective sensor finger and extends outwardly toward the other sensor finger. Each lever arm includes a pin receiver, the pin receivers being alignable with one another. A pin is mutually received by both pin receivers. A spring is connected to the pin and biases the pin downwardly such that the sensor finger tips are pulled toward one another.
A first linear actuator or lift cylinder, which may be pneumatically operated, is connected between the pin and the frame member. With the lift cylinder connected in this fashion, extension of the lift cylinder both moves the carriage upwardly toward the sausage support and pivots the tips of the sensor fingers away from each other in opposition to the spring bias. Retraction of the lift cylinder moves the carriage downwardly and allows the spring bias to pivot the sensor fingers tips toward one another. An air control valve mounted on the carriage proximate one of the sensor fingers is operatively connected to the lift cylinder such that closure of the air control valve will stop retraction of the cylinder. The air control valve includes a trigger which is engaged by a lever on the adjacent sensor finger upon inward movement of the sensor finger to close the valve.
A casing end-cutter comprising an air motor with a circular blade is pivotally connected to the carriage. A second linear actuator or pivot cylinder is connected between the end-cutter and the carriage for moving the end-cutter between a retracted position and a cutting position. In the cutting position, the blade is positioned immediately above the tips of the sensor fingers.
As the lift cylinder retracts and the carriage moves away from the lower end of the sausage support, the sensor finger tips slidingly engage a sausage supported on the sausage support. When the tips reach the bottom end of the sausage, the spring causes the sensor fingers to move inwardly, following the converging sides of the sausage. The inward movement of the fingers actuates the air control valve trigger, stopping the carriage. The casing cutter is then moved into the cutting position to cut off the lower end of the casing above the sensor finger tips. As the carousel continues to rotate, a plate supports the lower end of the sausage so that it cannot fall out of the casing prematurely.
As the main conveyor moves the sausages off of the carousel, the sausages are supported in a generally upright position by a second conveyor positioned below the main conveyor. The second conveyor comprises a belt with vertical slats forming sausage supporting slots therebetween. A plate continues to support the bottom ends of the sausages.
A pair of stripper bars are positioned below the main conveyor and above the second conveyor for engaging the top ends of the sausages. The string loops which connect the sausages to the main conveyor pass between the stripper bars, however the bars are spaced sufficiently close to one another that the sausages cannot pass between them. The portion of the main conveyor above the stripper bars is angled upwardly such that the tops of the sausages are pulled against the stripper bars. The tension thus created in the string loops acts to pull the casings off of the sausages. The empty casings continue along the main conveyor to a holding bin. The sausages are temporarily supported by second conveyor until they reach the end of the bottom plate, at which point the sausages drop onto a high speed conveyor which transports them to a slicing station.